JP2022048496A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can prevent the omission of attachment of a belt to improve workability.SOLUTION: An image forming apparatus 1 comprises: a top cover 11 that is provided rotatably with respect to the image forming apparatus and opens or closes an opening 10A formed in an upper part of the image forming apparatus; a plurality of cartridges PC that have photoreceptors 51; exposure means 40 that are held by the top cover and expose the photoreceptors; a belt 73 that is arranged below the cartridges and removably attached to the image forming apparatus from the opening in a state in which the plurality of cartridges are removed; a plurality of guides that guide the cartridges removably attached to the image forming apparatus from the opening; a shutter that is provided to be movable to a position for closing entrances of the guides and a position for opening the entrances; and a link that moves the shutter to the position for opening the entrances of the guides in conjunction with the operation to attach the belt to the image forming apparatus, and moves the shutter to the position for closing the entrances of the guides in conjunction with the operation to remove the belt.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus such as a copying machine or a printer that forms an image on a sheet.

Patent Document 1 discloses an example of a conventional image forming apparatus. The image forming apparatus disclosed in Patent Document 1 has an endless belt that circulates with a substantially horizontal belt surface inside an apparatus main body provided with a conveying path for conveying a sheet, and an upper side with respect to the belt. It is equipped with four cartridges facing each other and arranged in the longitudinal direction of the belt surface. The cartridge is a unit in which a photoconductor, a developing means, and the like are integrated.

An openable top cover is provided on the upper surface of the main body of the image forming apparatus so as to cover the upper part of the cartridge. This top cover can be rotated around an axis provided on the rear side of the main body of the device along the left-right direction, and can be displaced to an open position where the front end is rotated upward to take an inclined posture. It has become. Inside the top cover, a scanner unit that exposes the photoconductor in the cartridge is held. By setting the top cover in the open position, the upper part of the cartridge is opened, and each cartridge can be attached and detached through the opening in the upper part of the apparatus main body thus formed.

By the way, the belt may also be replaced due to deterioration over time. Further, when a paper jam occurs in the image forming apparatus, the belt itself may be removed to clear the paper jam. In the image forming apparatus disclosed in Patent Document 1, first, all the cartridges are removed, and then the belt is removed.

Japanese Unexamined Patent Publication No. 2006-98776

However, in the configuration in which all the cartridges are removed from the main body of the device and then the belt is removed as in the image forming apparatus disclosed in Patent Document 1, there is a possibility that the cartridges may be attached in a state where the belt is forgotten to be attached. .. In that case, it is necessary to remove all the mounted cartridges again, which causes a problem of poor workability.

Therefore, an object of the present invention is to prevent forgetting to attach the transfer belt and improve workability.

In order to achieve the above object, the present invention is an image forming apparatus for forming an image on a sheet, which is rotatably provided with respect to the image forming apparatus about a rotation axis and is an upper portion of the image forming apparatus. A top cover that can be moved to a first position for closing the opening and a second position for opening the opening, and a photoconductor that can be attached to and detached from the opening to the image forming apparatus. A plurality of cartridges, an exposure means held by the top cover to expose the photoconductor, and an endless belt arranged below the cartridges, in a state where the plurality of cartridges are removed. A belt that can be attached to and detached from the opening to the image forming apparatus, a plurality of guides that guide each cartridge that is attached to and detached from the opening to the image forming apparatus, and a position that closes and opens the entrance of the guide. In conjunction with the movable shutter and the mounting operation of the belt on the image forming apparatus, the shutter is moved to a position where the inlet of the guide is opened, and the belt from the image forming apparatus is moved. It is characterized by including a link that moves the shutter to a position that closes the entrance of the guide in conjunction with the removal operation.

According to the present invention, since the cartridge cannot be attached to the apparatus main body when the belt is not attached, it is possible to prevent forgetting to attach the belt and improve workability.

Schematic block diagram of a color printer Diagram showing a color printer with the top cover open The figure which shows the guide member and the interlocking member before mounting the transfer belt which concerns on Example 1. A perspective view showing a guide member and an interlocking member before mounting the transfer belt according to the first embodiment. The figure which shows the guide member and the interlocking member after wearing the transfer belt which concerns on Example 1. A perspective view showing a guide member and an interlocking member after the transfer belt is attached according to the first embodiment. FIG. 6 is a relationship diagram showing an exposure head, a photosensitive drum, a guide member, and an interlocking member according to the first embodiment. The figure which shows the guide member and the interlocking member before mounting the transfer belt which concerns on Example 2. A perspective view showing a guide member and an interlocking member before mounting the transfer belt according to the second embodiment. The figure which shows the guide member and the interlocking member after the transfer belt is attached which concerns on Example 2. A perspective view showing a guide member and an interlocking member after the transfer belt is attached according to the second embodiment. FIG. 6 is a relationship diagram showing an exposure means, a guide member, and an interlocking member according to the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail exemplary with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the following examples should be appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions. It is not intended to limit the scope of the invention to those alone.

[Example 1]
The image forming apparatus according to the first embodiment will be described with reference to FIGS. 1 to 7. Here, as the image forming apparatus, an electrophotographic image forming apparatus (color printer) will be illustrated and described.

FIG. 1 is a schematic configuration diagram of a color printer, and FIG. 2 is a diagram showing a color printer with the top cover open. FIG. 3 is a diagram showing a guide member and an interlocking member before the transfer belt is attached. FIG. 4 is a perspective view showing a guide member and an interlocking member before the transfer belt is attached. FIG. 5 is a diagram showing a guide member and an interlocking member after the transfer belt is attached. FIG. 6 is a perspective view showing a guide member and an interlocking member after the transfer belt is attached. FIG. 7 is a diagram showing the positional relationship between the exposure head, the photosensitive drum, the guide member, and the interlocking member.

In the following description, the direction will be described in the direction shown in FIG. That is, the upper side in FIG. 1 is referred to as "upper" and the lower side is referred to as "lower". The upper side in FIG. 1 is the upper side in the vertical direction, and the lower side is the lower side in the vertical direction. Further, in FIG. 1, the left side is "front", the right side is "rear", the back side is "left", and the front side is "right". The left side in FIG. 1 is one side in the first horizontal direction orthogonal to the vertical direction, and the right side is the other side in the first horizontal direction. The back side in FIG. 1 is one side in the second horizontal direction orthogonal to the vertical direction and the first horizontal direction, and the front side is the other side in the second horizontal direction.

As shown in FIG. 1, the color printer 1 as an image forming apparatus includes a main body housing 10 which is an apparatus main body, a top cover 11, a feeding unit 20, and an image forming unit 30. Further, in the main body housing 10, a temperature sensor 15 for detecting the temperature inside the main body housing 10, a patch detection sensor 75 as an example of the sensor, and a control unit 800 for controlling the operation of the printer are provided. ing. Further, as shown in FIGS. 3 and 4, a guide member 12 and an interlocking member 17 (shutter 13 and link 16) are provided inside the main body housing 10.

The top cover 11 is arranged on the upper part of the main body housing 10 and is rotatably provided with respect to the main body housing 10 around the rotation shaft 11A on the rear side of the main body housing 10. The opening 10A formed in the upper part is opened and closed. Specifically, the top cover 11 has a first position (position shown in FIG. 1) for closing the opening 10A and a second position (shown in FIG. 2) for opening the opening 10A with the rotation shaft 11A as the center. It is possible to move to (position).

The feeding unit 20 is provided at the lower part in the main body housing 10. The feeding unit 20 includes a feeding tray 21 for accommodating the paper P as a sheet, and a paper supply mechanism 22 for supplying the paper P from the feeding tray 21 to the image forming unit 30. The paper P in the feed tray 21 is separated one by one by the paper supply mechanism 22 and supplied to the image forming unit 30.

The image forming unit 30 includes four exposure heads 40, four process cartridge PCs, a transfer unit 70, and a fixing unit 80.

The exposure head 40 as an exposure means has a light emitting element and an imaging lens at its tip. The exposure head 40 exposes the surface of the cylindrical photosensitive drum 51, which is a photoconductor, by blinking the light emitting element based on the image data. The exposure head 40 is held inside the top cover 11 so as to be suspended from the top cover 11. The exposure head 40 is arranged facing above the photosensitive drum 51 in the state shown in FIG. 1 with the top cover 11 closed. Specifically, the exposure head 40 has a reference position (position shown in FIG. 1) closer to the photosensitive drum 51 and a retracted position (FIG. 2) farther from the photosensitive drum 51 than the reference position by opening and closing the top cover 11. It is possible to move between the position shown).

The process cartridge PC has a cylindrical photosensitive drum 51 that is a photoconductor, and at least one process means that acts on the photosensitive drum 51. The process means include a charger 52 as a charging means, a developing roller 62 as a developing means, a cleaning roller 54 as a cleaning means, and the like, which will be described later.

Each process cartridge PC is arranged in parallel between the top cover 11 and the feed tray 21 along the front-rear direction. Each process cartridge PC is detachable from the opening 10A to the main body housing 10 in the state shown in FIG. 2 when the top cover 11 is opened. When each process cartridge PC is mounted on the main body housing 10, it is guided and positioned by each guide 12A (see FIG. 3) provided on the main body housing 10. Each process cartridge PC includes a drum unit 50 and a developing cartridge 60 as an example of a developing device. The developing cartridge 60 is removable from the drum unit 50.

The drum unit 50 includes a cylindrical photosensitive drum 51 which is a photoconductor, a scorotron type charger 52 for charging the photosensitive drum 51, a pressing spring 53 for urging the developing cartridge 60 toward the photosensitive drum 51, and a cleaning roller. It includes a 54 and a drum frame 55 that supports the photosensitive drum 51 and the like.

The developing cartridge 60 mainly includes a toner accommodating portion 61 for accommodating toner and a developing roller 62 for supplying the toner in the toner accommodating portion 61 to the photosensitive drum 51. The toner is a developer that develops an electrostatic latent image on the photosensitive drum 51. The toner accommodating portion 61 of each developing cartridge 60 contains yellow, magenta, cyan, and black toners in order from the front (left side in FIG. 1).

The transfer unit 70 is a belt unit having a drive roller 71 which is a tension member and a transport belt 73 which is an endless belt stretched by a driven roller 72. Here, the configuration in which the transfer unit 70, which is a belt unit, has a transport belt 73 for transporting the paper P as a sheet is illustrated.

The transfer unit 70 is arranged below the process cartridge PC and is provided between the feed tray 21 and the process cartridge PC. The transfer unit 70 includes a drive roller 71, a driven roller 72, an endless transfer belt 73 as an example of a transfer medium, and four transfer rollers 74 as an example of a transfer device. The transport belt 73 is stretched between the drive roller 71 and the driven roller 72, which are stretch members. The outer surface of the transport belt 73 is in contact with each photosensitive drum 51, and each transfer roller 74 is arranged inside the transport belt 73 so as to sandwich the transport belt 73 with each photosensitive drum 51.

The transfer unit 70 can be removed from the main body housing 10 with all the process cartridge PCs removed. That is, when it is desired to remove the transfer unit 70 from the main body housing 10, first remove all the process cartridge PCs. Here, the "state in which the process cartridge PC is removed" means a state in which the process cartridge PC is completely separated from the main body housing 10 and removed. That is, when the state in which the process cartridge PC is completely mounted on the main body housing 10 (the state in which the image forming operation can be performed) is defined as the mounted state, it means that the mounted state is only released from this mounted position. I don't do it. That is, the state in which the process cartridge PC is completely removed from the guide 12A described later is defined as the "state in which the process cartridge PC is removed".

A patch detection sensor 75 is provided diagonally below the rear of the conveyor belt 73. The patch detection sensor 75 is a sensor that detects the print density of the toner image for density correction formed on the transfer belt 73, and is arranged so as to face the rear portion of the transfer belt 73. In the following description, the toner image for density correction formed on the transport belt 73 is also referred to as a “patch”. The patch detection sensor 75 is a light reflection type sensor including a light emitting element such as an LED and a light receiving element such as a phototransistor, and irradiates the patch with light to detect the reflected light.

The transfer unit 70 is detachable through the opening 10A of the main body housing 10 after removing each process cartridge PC in a state where the top cover 11 is opened (see FIG. 2).

The guide member 12 and the interlocking member 17 (shutter 13 and link 16) related to the attachment / detachment of the process cartridge PC and the transfer unit 70 will be described later.

The fixing unit 80 is provided behind the process cartridge PC and the transfer unit 70. The fixing unit 80 includes a heating roller 81 and a pressure roller 82 that is pressed toward the heating roller 81.

In such an image forming unit 30, the surface of the photosensitive drum 51 is uniformly charged by the charger 52 and then exposed by the exposure head 40, so that the electrostatic latent on the photosensitive drum 51 is based on the image data. An image is formed. Then, by applying a voltage (development bias) to the developing roller 62, toner is supplied from the developing roller 62 to the photosensitive drum 51, an electrostatic latent image is visualized, and a toner image is formed on the photosensitive drum 51. Will be done. That is, the developing cartridge 60 develops the electrostatic latent image on the photosensitive drum 51.

The toner image formed on each photosensitive drum 51 is sequentially superposed on the paper P transported on the transport belt 73 and transferred by the transfer roller 74. The paper P on which the toner image is transferred is conveyed between the heating roller 81 and the pressure roller 82, so that the toner image is thermally fixed. After that, the paper P is discharged from the inside of the main body housing 10 to the outside by the transport roller 91, and is placed on the discharge tray 11B formed on the upper surface of the top cover 11. The toner remaining on the photosensitive drum 51 after transfer is recovered by the cleaning roller 54.

Next, the guide member 12 and the interlocking member 17 (shutter 13 and link 16) provided inside the main body housing 10 related to the attachment / detachment of the process cartridge PC and the transfer unit 70 will be described. As shown in FIGS. 3 and 4, the guide member 12 is fixed to the inside of the main body housing 10. The guide member 12 has a plurality of guides 12A that guide and position each process cartridge PC that is attached to and detached from the main body housing 10. Each guide 12A has an inlet 12B opened at the top for removing the process cartridge PC from the opening 10A formed in the upper part of the main body housing 10 and mounting the process cartridge PC from the opening 10A to the main body housing 10. .. The guide members 12 are provided on the left and right sides inside the main body housing 10 so as to support and guide both sides of the process cartridge PC in the left-right direction of the main body housing 10 (see FIG. 7). In the guide member 12, each guide 12A guides both sides of each process cartridge PC mounted on the main body housing 10 in the left-right direction, and positions the process cartridge PC with respect to the main body housing 10.

As shown in FIGS. 3 and 4, the interlocking member 17 is integrally provided with the shutter 13 and the link 16. The shutter 13 is for closing the inlet 12B of each guide 12A. The shutter 13 is provided inside the main body housing 10 and is provided so as to be movable in the front-rear direction, which is the arrangement direction of the plurality of guides 12A of the guide member 12, with respect to the guide member 12 fixed to the main body housing 10. Has been done. The shutter 13 can move in the front-rear direction between the position where the inlet 12B of each guide 12A is opened (see FIGS. 5 and 6) and the position where the inlet 12B of each guide 12A is closed (see FIGS. 3 and 4). It is provided in. In this embodiment, the shutter 13 has an opening 13B for opening the inlet 12B of the guide 12A. Here, as shown in FIGS. 4 and 6, the shutter 13 exemplifies a configuration having a plurality of openings 13B that open all the inlets 12B of each guide 12A. Here, the "guide entrance" refers not only to the opening above the guide 12A but also to a region from the opening to about several hundred mm. That is, the shutter 13 may be positioned in the middle of the guide 12A to prevent the process cartridge PC from being inserted. In this case, the process cartridge PC can be inserted halfway through the guide 12A, but the user can notice that the process cartridge PC cannot be inserted because the process cartridge PC is caught in the middle. However, in this configuration, the user does not notice that the shutter 13 is closed unless the process cartridge PC is inserted halfway through the guide 12A. Therefore, as in the present embodiment, the shutter is in front of the entrance 12B of the guide 12A. It is preferable to provide 13. Further, when it is said that the entrance is closed, it includes not only a state in which the opening is completely closed by the shutter 13, but also a state in which a part of the opening is closed and the insertion / removal of the process cartridge PC is hindered.

The link 16 moves the shutter 13 to a position where the inlet 12B of the guide 12A is opened or closed in conjunction with the operation of attaching and detaching the transfer unit 70 to the image forming apparatus. The link 16 is provided inside the main body housing 10 so as to be movable in an intersecting direction intersecting in a direction in which the transfer unit 70 is attached / detached to / from the image forming apparatus. Here, the moving direction of the link 16 is the front-back direction, which is the crossing direction intersecting the vertical direction, which is the attachment / detachment direction of the transfer unit 70 with respect to the image forming apparatus. The link 16 has an inclined surface 16A as a cam surface that abuts on a part of the transfer unit 70 mounted on the main body housing 10. The inclined surface 16A moves the link 16 in the front direction, which is one direction in the front-rear direction, in conjunction with the mounting operation of the transfer unit 70 in contact with the cam surface, and this movement moves the shutter 13 to the closing position. It is an inclined surface. That is, the inclined surface 14A of the link 16 moves the shutter 13 in the arrow F direction (from the rear side to the front side of the main body housing 10) in conjunction with the downward movement of the transfer unit 70 in contact with the inclined surface 14A. It functions as a cam surface to move in the direction). The link 16 is urged from the front side to the rear side of the main body housing 10 by an urging means (not shown). In the urging means (not shown), one end is fixed to the main body housing 10, the other end is fixed to the link 16, and the link 16 is urged from the front side to the rear side of the main body housing 10. ing. That is, the link 16 moves the shutter 13 to a position where the inlet 12B of the guide 12A is opened in conjunction with the mounting operation of the transfer unit 70 to the image forming apparatus. Further, the link 16 moves the shutter 13 to a position that closes the inlet 12B of the guide 12A in conjunction with the operation of removing the transfer unit 70 from the image forming apparatus.

Here, the configuration in which the link 16 is urged toward the rear side by the urging means is illustrated, but the present invention is not limited to this. For example, the link 16 may be urged toward the front side by the urging means. In this case, the inclined surface 16A of the link 16 moves the link 16 in the direction opposite to the one direction of the crossing direction in conjunction with the removal operation of the transfer unit 70 in contact with the cam surface, and this movement causes the link 16 to move in the direction opposite to the one direction of the crossing direction. The inclined surface is used to move the shutter 13 to the open position. Alternatively, the link 16 has no urging means and has only the cam surface, and moves in conjunction with the movement of the transfer unit that moves in contact with the cam surface, and the shutter is moved by the movement. good.

In a state where the transfer unit 70 is removed from the main body housing 10, the link 16 is urged toward the rear side by an urging means (not shown) and abutted against the guide member 12, and the shutter 13 is shown in FIGS. It is stopped at the closing position shown in 4. Here, a guide member is exemplified as a stopper for stopping the interlocking member integrally provided with the shutter 13 and the link 16 at the closing position, but the present invention is not limited to this, and a separate stopper is provided. It may be configured as a new type. In the interlocking member 17 stopped at the closing position shown in FIGS. 3 and 4, the shutter 13 closes the inlet 12B of each guide 12A. Therefore, it is not possible to mount each process cartridge PC before the transfer unit 70 is mounted.

When the transfer unit 70 is attached to the main body housing 10, the transfer unit 70 is moved downward (in the direction of arrow D shown in FIG. 3). At this time, a part of the transfer unit 70 comes into contact with the inclined surface (cam surface) 16A of the link 16. The link 16 is moved forward (in the direction of arrow F shown in FIG. 5) against the urging force of the urging means as the transfer unit 70 abuts on the inclined surface 16A moves downward. Ru. That is, the interlocking member 17 is moved to a position where the inlet 12B of the guide 12A is opened in conjunction with the operation of mounting the transfer unit 70 in contact with the inclined surface 16A of the link 16 on the main body housing 10. As a result, as shown in FIG. 6, each opening 13B of the shutter 13 opens the inlet 12B of each guide 12A, and each process cartridge PC is mounted on the main body housing 10 from the inlet 12B of each guide 12A. Is possible. The timing of starting the "mounting operation" referred to here means the timing at which the transfer unit 70 comes into contact with the inclined surface 16A of the link 16. Further, the timing of the end of the "mounting operation" means the timing at which the movement of the link 16 is stopped. That is, it is not necessary to consider the moment when a part of the transfer unit 70 approaches the opening 10A as the timing at which the "mounting operation" starts.

On the other hand, when the transfer unit 70 is removed from the main body housing 10, the transfer unit 70 is moved upward (in the direction opposite to the arrow D direction shown in FIG. 3). The interlocking member 17 is moved in the rear direction (opposite to the arrow F direction shown in FIG. 5) by the urging force of the urging means as the transfer unit 70 moves upward. That is, the interlocking member 17 moves to a position where the entrance 12B of the guide 12A is closed by the urging force of the urging means in conjunction with the operation of removing the transfer unit 70 in contact with the inclined surface 16A of the link 16 from the main body housing 10. Will be moved. As a result, as shown in FIG. 4, the shutter 13 closes the inlet 12B of each guide 12A, and the process cartridge PC cannot be mounted before the transfer unit 70 is mounted.

When the shutter 13 is moved to a position where the inlet 12B of each guide 12A is opened, the transfer unit 70 is engaged with an engaging portion (not shown) provided on the main body housing 10 side, and the main body housing 10 is engaged. Positioned against.

Further, as shown in FIG. 7, the exposure head 40 exposes the image forming region of the photosensitive drum 51, but the guide member 12 (guide 12A) and the shutter 13 are the photosensitive drum 51 in the left-right direction of the main body housing 10. It is arranged outside the image forming region and further outside the exposure head 40. Therefore, the guide member 12 and the shutter 13 do not interfere with the exposure head 40 when opening and closing the top cover 11, and do not hinder the movement of the top cover 11 and the exposure head 40.

As described above, by providing the link 16 that moves the shutter 13 to the position where the inlet 12B of the guide 12A is closed or opened in conjunction with the insertion and removal of the transfer unit 70, the shutter 13 is provided when the transfer unit 70 is not attached. Is designed to block the entrance 12B of the guide 12A. Therefore, the process cartridge PC cannot be mounted before the transfer unit 70 is mounted on the main body housing 10. Therefore, it is possible to eliminate forgetting to attach the transfer unit 70 and improve workability.

Further, since the shutter 13 and the link 16 are integrally provided as the interlocking member 17, the number of parts is reduced, the cost is low, the transfer unit 70 is not forgotten to be attached, and the workability can be improved.

Further, the guide member 12 (guide 12A) and the shutter 13 are arranged outside the image forming region of the photosensitive drum 51 and further outside the exposure head 40 in the left-right direction of the main body housing 10. Therefore, the guide member 12 and the shutter 13 do not interfere with the exposure head 40 when opening and closing the top cover 11, and do not hinder the movement of the top cover 11 and the exposure head 40.

In this embodiment, the shutter 13 opens and closes the inlets 12B of all the guides 12A, but the present invention is not limited to this. The shutter may cover only the inlet of any one or more process cartridge guides when the transfer unit 70 is not mounted. Further, in this embodiment, a configuration in which the shutter 13 is provided on both sides in the left-right direction of the main body housing 10 which is the longitudinal direction of the photosensitive drum 51 is exemplified, but the present invention is not limited to this, and the shutter 13 is provided only on one side. It may be configured as a new type.

[Example 2]
Hereinafter, Example 2 of the present invention will be described with reference to the drawings. FIG. 8 is a diagram showing a guide member and an interlocking member before the transfer belt is attached. FIG. 9 is a perspective view showing a guide member and an interlocking member before the transfer belt is attached. FIG. 10 is a diagram showing a guide member and an interlocking member after the transfer belt is attached. FIG. 11 is a perspective view showing a guide member and an interlocking member after the transfer belt is attached. FIG. 12 is a diagram showing the positional relationship between the exposure head, the photosensitive drum, the guide member, and the interlocking member.

In the above-described embodiment, the interlocking member 18 (shutter 13) covers the inlets 12B of all the guides 12A when the transfer unit 70 is not mounted, but the present invention is not limited thereto. For example, when the transfer unit 70 is not mounted, it may cover the inlet 12B of the guide 12A of any one or more process cartridge PCs. In this embodiment, the interlocking member 18 (shutter 14) covers only the inlet of one of the inlets 12B of the plurality of guides 12A when the transfer unit 70 is not mounted.

In the following description, the same reference numerals will be used for those having the same configuration as that of the first embodiment described above, and the description thereof will be omitted.

The interlocking member 18 is integrally provided with a shutter 14 and a link 16. The shutter 14 closes only the inlet of one of the inlets 12B of the plurality of guides 12A when the transfer unit 70 is not mounted. The shutter 14 has a closing portion 14C for closing the inlet 12B of the guide 12A for the frontmost process cartridge PC in the guide member 12. Here, in the front-rear direction of the main body housing 10, the frontmost guide 12A for the process cartridge PC is the guide 12A adjacent to the shutter 14. Since the configuration of the link 16 is the same as that of the above-described embodiment, the members having the same function are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIGS. 8 and 9, when the transfer unit 70 is removed from the main body housing 10, the link 16 is urged toward the rear side by an urging means (not shown) and thrusts into the guide member 12. It is hit and the shutter 14 is stopped at the closing position shown in FIGS. 8 and 9. Here, a guide member is exemplified as a stopper for stopping the interlocking member integrally provided with the shutter 14 and the link 16 at the closing position, but the present invention is not limited to this, and a separate stopper is provided. It may be configured as a new type. In the interlocking member 18 stopped at the closing position shown in FIGS. 8 and 9, the shutter 14 closes the entrance 12B of one guide 12A in the foreground. Therefore, before the transfer unit 70 is mounted, the frontmost process cartridge PC cannot be mounted.

When the transfer unit 70 is attached to the main body housing 10, the transfer unit 70 is moved downward (in the direction of arrow D shown in FIG. 8). At this time, a part of the transfer unit 70 comes into contact with the inclined surface (cam surface) 16A of the link 16. The link 16 is moved forward (in the direction of arrow F shown in FIG. 10) against the urging force of the urging means as the transfer unit 70 abuts on the inclined surface 16A moves downward. Ru. That is, the interlocking member 18 is in a position to open the inlet 12B of one of the foremost guides 12A in conjunction with the operation of mounting the transfer unit 70 in contact with the inclined surface 16A of the link 16 on the main body housing 10. Moved to. As a result, as shown in FIG. 11, the shutter 13 opens the inlet 12B of each guide 12A in the foreground, and the process cartridge PC is mounted on the main body housing 10 from the inlet 12B of the guide 12A. Is possible.

On the other hand, when the transfer unit 70 is removed from the main body housing 10, the transfer unit 70 is moved in the upward direction (direction opposite to the arrow D direction shown in FIG. 8). The interlocking member 18 is moved in the rear direction (opposite to the arrow F direction shown in FIG. 10) by the urging force of the urging means as the transfer unit 70 moves upward. That is, the interlocking member 18 is interlocked with the operation of removing the transfer unit 70 abutting on the inclined surface 16A of the link 16 from the main body housing 10, and the foremost guide 12A is provided by the urging force of the urging means. It is moved to a position that blocks the entrance 12B. As a result, as shown in FIG. 9, the shutter 14 closes the inlet 12B of one guide 12A in the foreground, and the process cartridge PC in the foreground cannot be attached before the transfer unit 70 is attached. ..

Further, as shown in FIG. 12, the exposure head 40 exposes the image forming region of the photosensitive drum 51, but the guide member 12 (guide 12A) exposes the image forming region of the photosensitive drum 51 in the left-right direction of the main body housing 10. It is arranged outside the exposure head 40 and further outside the exposure head 40. Further, the shutter 14 and the closing portion 14C are arranged on one side (here, the left side) in the left-right direction of the main body housing 10 outside the image forming region of the photosensitive drum 51, and further outside the exposure head 40. Therefore, the guide member 12 and the shutter 14 do not interfere with the exposure head 40 when opening and closing the top cover 11, and do not hinder the movement of the top cover 11 and the exposure head 40.

As described above, by providing the link 16 that moves the shutter 13 to the position where the inlet 12B of the guide 12A is closed or opened in conjunction with the insertion and removal of the transfer unit 70, the shutter 14 is provided when the transfer unit 70 is not attached. Is designed to block the entrance 12B of the foremost guide 12A. Therefore, it is not possible to mount the frontmost process cartridge PC before mounting the transfer unit 70. Therefore, it is possible to eliminate forgetting to attach the transfer unit 70 and improve workability.

Further, the shutter 14 and the link 16 are integrally provided as an interlocking member 18, and only the entrance 12B of the frontmost guide 12A is closed. Therefore, the parts can be made compact, the number of parts can be reduced, the cost can be reduced, the transfer unit 70 can be not forgotten to be attached, and the workability can be improved.

Further, the guide member 12 (guide 12A) and the shutter 14 are arranged outside the image forming region of the photosensitive drum 51 and further outside the exposure head 40 in the left-right direction of the main body housing 10. Therefore, the guide member 12 and the shutter 14 do not interfere with the exposure head 40 when opening and closing the top cover 11, and do not hinder the movement of the top cover 11 and the exposure head 40.

In this embodiment, the shutter is configured to close the inlet 12B of the guide 12A of any one or more process cartridge PCs when the transfer unit 70 is not attached, and the shutter 14 is one when the transfer unit 70 is not attached. The configuration that blocks only the entrance of the guide is illustrated. However, the present invention is not limited to this, and any configuration may be used as long as it covers any one or more guide portions. Further, in this embodiment, the configuration in which the shutter 14 is provided on only one side (left side) in the left-right direction of the main body housing 10 which is the longitudinal direction of the photosensitive drum 51 is illustrated, but the present invention is not limited thereto. The shutter 14 may be provided only on the other side (right side) in the left-right direction of the main body housing 10, or may be provided on both sides.

[Other Examples]
In the above-described embodiment, the configuration in which the shutter and the link are integrally provided is illustrated, but the present invention is not limited to this, and the shutter and the link may be provided separately. Further, the link 16 exemplifies a configuration having an inclined surface 16A that abuts on a part of the transfer unit 70 mounted on the main body housing 10, but is not limited thereto. The link may have any other configuration as long as it is configured to move the shutter to a position where the entrance of the guide is opened or closed in conjunction with an operation of attaching or detaching the belt to the image forming apparatus.

Further, in the above-described embodiment, four process cartridges are used, but the number of used process cartridges is not limited and may be appropriately set as needed.

Further, in the above-described embodiment, a process having a photosensitive drum as a cartridge that can be attached to and detached from the main body housing of the image forming apparatus, and a charging means, a developing means, and a cleaning means as process means acting on the photosensitive drum. An example of a cartridge. However, it is not limited to this. In addition to the photosensitive drum, a cartridge having any one of a charging means, a developing means, and a cleaning means may be used.

Further, in the above-described embodiment, the configuration in which the cartridge including the photosensitive drum is detachable from the main body housing is exemplified, but the present invention is not limited to this. For example, the photosensitive drum and each process means may be detachable.

Further, in the above-described embodiment, the printer is exemplified as the image forming apparatus, but the present invention is not limited thereto. For example, it may be another image forming apparatus such as a copying machine or a facsimile apparatus, or another image forming apparatus such as a multifunction device combining these functions. Similar effects can be obtained by applying the present invention to these image forming devices.

Further, in the above-described embodiment, a transport belt for transporting a sheet is exemplified as a belt, and an image forming apparatus for sequentially superimposing and transferring toner images of each color on a sheet supported on the transport belt is exemplified, but the present invention is limited to this. It is not something that is done. The belt may be an intermediate transfer belt (intermediate transfer body) that once supports the toner image formed on each photosensitive drum. An image forming apparatus may be used in which toner images of each color are sequentially superimposed and transferred to the intermediate transfer belt, and the toner images supported on the intermediate transfer belt are collectively transferred to a sheet. Similar effects can be obtained by applying the present invention to such an image forming apparatus.

P ... Paper PC ... Process cartridge 1 ... Color printer 10 ... Main body housing 10A ... Opening 11 ... Top cover 11A ... Rotating shaft 12 ... Guide member 12A ... Guide 12B ... Entrance 13 ... Shutter 13B ... Opening 14 ... Shutter 14C ... Closed part 16 ... Link 16A ... Inclined surface 17, 18 ... Interlocking member 30 ... Image forming part 40 ... Exposure head 50 ... Drum unit 51 ... Photosensitive drum 52 ... Charger 60 ... Development cartridge 61 ... Toner storage part 62 ... Development roller 70 ... Transfer unit 71 ... Drive roller 72 ... Driven roller 73 ... Conveyance belt 75 ... Patch detection sensor 80 ... Fixing unit

Claims (9)

An image forming device that forms an image on a sheet.
A first position that is rotatably provided about the image forming apparatus about a rotation axis and closes an opening formed in the upper part of the image forming apparatus, and a second position that opens the opening. With a movable top cover,
A plurality of cartridges that are removable from the opening to the image forming apparatus and have a photoconductor, and
An exposure means that is held by the top cover and exposes the photoconductor,
An endless belt arranged below the cartridge, and a belt that can be attached to and detached from the opening to the image forming apparatus when the plurality of cartridges are removed.
A plurality of guides for guiding each cartridge attached to and detached from the opening to the image forming apparatus, and
A shutter provided so as to be movable between a position where the entrance of the guide is closed and a position where the entrance of the guide is opened,
The shutter is moved to a position where the inlet of the guide is opened in conjunction with the operation of attaching the belt to the image forming apparatus, and the shutter is moved in conjunction with the operation of removing the belt from the image forming apparatus. An image forming apparatus including a link that moves the guide to a position that closes the entrance. The image forming apparatus according to claim 1, wherein the guide and the shutter are provided outside the image forming region of the photoconductor and outside the exposure means. The image forming apparatus according to claim 1 or 2, wherein the shutter has an opening for opening the entrance of the guide. The image forming apparatus according to claim 3, wherein the shutter has a plurality of openings that open all the entrances of the guides. The image forming apparatus according to claim 1 or 2, wherein the shutter has one closing portion for closing the entrance of one guide adjacent to the shutter among the entrances of the guides. The image forming apparatus according to any one of claims 1 to 5, wherein the guide and the shutter are provided on both sides in the longitudinal direction of the photoconductor. The image forming apparatus according to any one of claims 1 to 5, wherein the guide and the shutter are provided on either one side in the longitudinal direction of the photoconductor. The image forming apparatus according to any one of claims 1 to 7, wherein the belt is a transport belt for transporting a sheet. The link is provided so as to be movable in an intersecting direction intersecting the image forming apparatus in the direction in which the belt is attached / detached, and has a cam surface that abuts on the belt.
The cam surface moves the link in one direction of the crossing direction in conjunction with the mounting operation of the belt in contact with the cam surface, and by this movement, the shutter is moved to the position where the shutter is closed, or the cam. An inclined surface that moves the link in the direction opposite to the one direction of the crossing direction in conjunction with the removal operation of the belt in contact with the surface, and moves the shutter to the opening position by this movement. The image forming apparatus according to any one of claims 1 to 8.

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